The present invention relates to an apparatus and method for efficiently removing humidity from inside a chamber.
A current trend in the telecommunications, electronics and other high-technology industries is to deploy an active electronic equipment into the outside environment. The electronic equipment is usually installed within a chamber housing electronic circuitry together with additional environmental equipment ensuring continuation in desired performance of the operational elements of the circuitry or equipment. More precisely, the additional environmental equipment comprises an apparatus to control humidity and temperature conditions to protect electronic components against deterioration in operation. Humidity is a significant factor contributing to the failure of active devices, especially when there is a need to operate at low temperatures. Moisture and condensation conditions do arise and may deleteriously affect circuitry elements or members such as electronic components upon printed circuit boards or may form electrical shorting bridges on printed circuit boards between circuit paths. Therefore the control of humidity in outside plant chambers is paramount to maintaining high reliability systems.
It is well known that dehumidifiers/humidity pumps may be designed by using thermoelectric coolers having, in operation, a cool side and a warm side with a maintained temperature differential between them, the cool side acting as a "cold spot" to condense vapour from the air. Prior art reveals numerous apparatus based on the thermoelectric coolers to remove excess moisture from chambers which otherwise causes damage to equipment or articles stored in the chambers. Most of them provide simple mechanical means and/or additional pumping for removing a liquid condensate from the chamber.
For example, U.S. Pat. No. 4,321,800 to Gifford, 1982 provides an apparatus for handling atmospheric condensate resulting from the operation of a dehumidifier structure wherein the container for the condensate is rocked, as the level of the condensate increases, by a shift in the centre of gravity of the container.
U.S. Pat. No. 5,375,421 to Hsieh, 1994 provides a portable thermoelectric dehumidifier suitable to dehumidify small chamber volumes and providing removal of the condensate through a drain valve connected with a hose or pipe for discharging the water outwardly.
U.S. Pat. Nos. 5,074,119, 1991 and 5,212,958, 1991 to Anderson provide a pump pack for automatic and continuous emptying of water condensate from a dehumidifier positioned below ground level or remotely from a gravity drain. Condensate collected in a water collection pan is withdrawn at a preselected water level by the pump and passes through the tubing to an elevated or remote drain means or to other appropriate areas for disposal.
In U.S. Pat. No. 4,712,382 to LeClear, 1986 the aforementioned problems are solved by usage of a dehumidifier with a low profile receptacle having operative components that discharge a liquid during operation. The receptacle includes an integral pivoting bar for allowing the receptacle to pivot from a first position to a second position in response to an accumulation of a predetermined amount of condensate, said actions being regulated by shutoff means for selectively energising said operative components.
All of the methods and apparatus for dehumidifying a chamber, described in the above prior art, utilise combinations of mechanical and electrical means to remove condensate from the chamber. Each of these apparatus requires the installation of additional equipment together with its disadvantageous periodic maintenance and the regular emptying of a condensate from a collection container.
The present invention seeks to provide apparatus and methods which will avoid the above problems.